Overwhelming global demand may limit initial supplies of the Galaxy S4 smartphone, Samsung said Wednesday, while both Sprint and T-Mobile USA confirmed there would be delays.

T-Mobile said the GS4 was scheduled to go on sale online at its website Wednesday, but that online sales will be delayed for possibly five days, and are expected to begin Monday, April 29. The carrier cited an “unexpected delay with inventory deliveries.”

Appears to be a go on AT&T and Verizon

The nation’s two largest carriers, AT&T and Verizon, appeared unaffected by the delays. AT&T on Wednesday said it is “on track” for launch of the GS4 in its stores on Saturday.

Verizon Wireless said its GS4s will still be available on May 30 for $199.99 after rebate and a two-year contract.

In a statement issued via email, Samsung said: “Due to overwhelming global demand of the Galaxy S4, the initial supply may be limited. We expect to fulfill inventory to meet demands in the coming weeks.” Samsung didn’t indicate which carriers are affected.

Pricing

Sprint is offering the GS4 for $249.99 with a two-year contract, while AT&T is selling it for $199.99 and a two-year contract.

Michael HomnickGalaxy S4

T-Mobile was expected to begin sales of the GS4 on Wednesday online, and lists it on its websitefor a down payment of $149.99 plus 24 monthly payments of $20 each, for a total of $629.99.

In its statement, T-Mobile apologized to customers for the delay and said it is “working with Samsung to deliver the device to T-Mobile customers as soon as possible.” It also said that “online availability is expected to begin on Monday, April 29.”

U.S. Cellular also has the device listed as a pre-order only on its site for $199.99 and a two-year contract, with no delivery date.

Other smaller U.S. carriers that will carry the device could not be reached for comment on whether they face supply-related delays.

The GS4 has a 5-in. Super AMOLED display with 441 pixels per inch, well above other smartphones. It runs Android version 4.2.2 and uses a 1.9 GHz Qualcomm Snapdragon 600 processor in the U.S. model. It also has a 13-megapixel rear camera, a 2-megapixel front camera, a 2,600 mAh battery, NFC and 4G LTE for carriers that support LTE.